In another sign of the reverberations of Syria’s bloody civil war, an explosion rocked southern Beirut on the first day of the Muslim holy month, Ramadan, injuring at least 53 people. The area is a stronghold of Hizballah, the Lebanese Shi’ite faction that has strongly backed the regime of Syria’s embattled President Bashar Assad. Though no group has claimed responsibility for the attack, Lebanon’s interior minister warned against those who want to deepen Sunni-Shi’ite tensions in the country’s capital, which is no stranger to brutal, sectarian violence.